Device for supporting pull out plates in a cabinet

ABSTRACT

A mechanism for mounting in a cabinet or the like for supporting and guiding a main plate and an auxiliary plate for movement between retracted rearward positions in the cabinet and extended forward positions outside the cabinet. The mechanism includes telescopic guide means for guiding the outermost plate into and out of the cabinet and also includes mechanism for lifting the inner plate vertically in the cabinet so the outer plate will slide underneath the inner plate. When the plates are in extended position, the inner plate moves downwardly so as to be co-planar with the outer plate.

H1 3,880,094 i451 Apr. 29, 1975 i 1 DEVICE FOR SUPPORTING PULL OUT PLATES IN A CABINET [751 Inventors: Wendelin Kopp. Peterzell; Karl Kneile, Holzmaden, Teck. both of Germany [731 Assignee: Robert Krause KG, Weilheim.

Teck. Germany 22 Filed: Dec.26,1973

211 App1.No.:428.325

[30] Foreign Application Priority Data Dec. 22. 1972 Germany 2263073 [52] U.S. Cl. 108/74 [51] Int. Cl A47b 1/04 [58] Field of Search 108/74. 73: 312/292 [56] References Cited UNITED STATES PATENTS 1.294.734 2/[919 Wcndl 108/74 Walter 108/74 Cooper v. 108/74 Primary li.\'uminerRoy D. Frazier Ass/stun! Examiner- Darrell Marquette Attorney, Agent. or Firm-Walter Becker 1 57] ABSTRACT A mechanism for mounting in a cabinet or the like for supporting and guiding a main plate and an auxiliary plate for movement between retracted rearward positions in the cabinet and extended forward positions outside the cabinet. The mechanism includes telescopic guide means for guiding the outermost plate into and out of the cabinet and also includes mechanism for lifting the inner plate vertically in the cabinet so the outer plate will slide underneath the inner plate. When the plates are in extended position. the inner plate moves downwardly so as to be co-p1anar with the outer plate.

26 Claims, 8 Drawing Figures DEVICE FOR SUPPORTING PULL OUT PLATES IN A CABINET The present invention relates to a fitting for extensibly mounting an auxiliary plate or the like such as a table or work plate on a support for instance on a kitchen furniture piece, with guiding means for the auxiliary plate which is adapted to be moved into a non-use position below another plate. while for purposes of lifting said other plate two members which when pushing in the auxiliary plate are located mutually in the path of movement. namely one intermediate member engaging the other plate and movably arranged transverse to the plane thereof, and a lifting member engaging said intermediate member. of which one member is arranged on said support whereas the other member is arranged on the other plate.

It is an object of the present invention so to design a fitting of this type that in spite of a simple construction an easy movement will be assured.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawings, in which:

FIG. I represents a vertical section through a portion of a furniture piece provided with a fitting according to the invention. FIG. 2 shows the top view of FIG. 1

FIG. 3 illustrates the arrangement of FIG. 1 but with the table plate pushed into the furniture piece.

FIG. 4 illustrates on a larger scale than FIG. I a portion of FIG. I with the table plate partially pulled out.

FIG. 5 illustrates the arrangement of FIG. 4 but with the table plate moved further into the furniture piece.

FIG. 6 shows the arrangement of FIGS. 4 and 5 with the table plate completely moved into the furniture piece.

FIG. 7 is a top view of the arrangement according to FIG. 6.

FIG. 8 shows the table plate in top view and in cornpletely pulled out condition.

The fitting for extensible mounting an auxiliary plate or the like such as a table or work plate on a support for instance a kitchen furniture piece, according to the present invention is characterized primarily in that the lifting member is mounted on the support. and that the intermediate member is mounted on the auxiliary plate. In this way a very simple assembly possibility and ac- Cessibility to the fitting is obtained.

Expediently. the other plate is likewise mounted so as to be able to be pulled out and preferably in the pullout direction is suspended on the auxiliary plate so that both plates can be entirely pulled out of the furniture piece or the like and can also be completely pushed into said furniture piece.

Expediently. the intermediate member is mounted within the region of that end of the other plate when occupying its starting position which faces toward the pulled out auxiliary plate so that the intermediate member can be designed relatively small and space saving.

The intermediate member and/or the lifting member may be arranged in a protective manner below the pertaining plate.

The intermediate member may be displaceablc for instance on an inclined path or in the manner of a rotating wedge may be mounted for rotation about a vertical axis. However, it is particularly expedient to pivot-ally mount the intermediate member for pivoting about a horizontal axis which is at a right angle to the pull-out direction of the plate.

In view of the design according to the present invention it is possible also to design the intermediate member in a simple manner substantially as a one-arm lever which is provided underneath said other plate and in the path of movement of the lifting member.

In order in spite of a compact design to realize favorable lever conditions, the intermediate member is in plan view offset substantially laterally with regard to the lifting member while it comprises a laterally protruding running element associated with said lifting member.

The engaging surface of the intermediate member may on the other plate and on the lifting member in a simple manner be designed by the same running element which preferably has rounded running surfaces.

In order to assure that the other plate can easily be lifted and can be lowered in a cushioning manner. the intermediate member is preloaded toward its lifting position, especially spring loaded. The lifting member may in a simple manner he designed as a curve which in the manner of a roof protrudes in upward direction and which will assure a uniform lifting of the other plate.

For a simple connection of the intermediate member with the other plate. the intermediate plate protrudes in a rearward direction beyond the auxiliary plate while preferably forming a support for the other plate occupying its pulled-out position.

In order to be able to lift and lower the other plate in a simple manner while avoiding a canting, two or more lifting elements are provided adjacent to each other, preferably on both sides of the plate.

According to a further development of the invention. the intermediate member is mounted on a hearing which is connected to the bottom side of the intermediate plate and which preferably forms a support which protrudes beyond the rear end of the auxiliary plate and is intended as support for the lowered other plate so that the two plates when in position of use will at any rate have the desired level. The preferably angle shape bearing may in a simple manner with one leg form the support and on a leg at a right angle thereto will support the intermediate member.

For purposes of further simplifying the design of the fitting, the lifting member is formed by a wire frame or the like which is preferably connected to the inner side of the guiding means. The said frame of wire or the like has round cross sections as a result of which an easier movement of the intermediate member will be assured.

According to a further suggestion of the present invention, a pull member is provided for suspending the other plate on the auxiliary plate. said pull member preferably being located below the plates. This pull member will only when the auxiliary plate is pulled out from below the other plate form a positive connection, especially exclusively in pull-out direction, between the plates so that the other plate does not have to be pulled out separately. According to a simple design in conformity with the present invention, the pull member is formed by a pull rod which is connected to the rear end of the other plate and extends in approximately pullout direction toward the front. Displaceably guided on said pull rod is a follower which is connected to the rear end of the auxiliary plate. Said pull rod comprises an abutment which preferably is adjustable and which is located in front of said follower and serves as abutment for the latter. When arranging the pull member in the longitudinal central plane of the table plate. a single pull member will suffice.

Expediently, the pull member is designed so as to be resilient in its longitudinal direction so that the other plate when pulling out the auxiliary plate will in cushioned manner be taken along and in addition thereto will when occupying its position of use he resiliently pulled against the auxiliary plate. According to a particularly simple embodiment of the invention. the pull member is resilient due to the fact that is comprises an angled-off part which extends transverse to the pull direction.

In order to assure a very easy movement of the pull member and a substantially play-free guiding in the follower. the pull member extends at an incline toward its rear end in downward direction while it is preferably adjacent to the rear end guided by an angled-off part with regard to the bottom side of the other plate.

In order to assure that the other plate is substantially uniformly lifted over its entire length and thus the auxiliary plate can practically contact-free move below the other plate. an inclined ramp is provided at the rear end of the guiding means for the other plate. the height of said ramp preferably corresponding to the lifting stroke of the intermediate member.

The guiding means for the plates may in a simple manner comprise a rail for at least one supporting member especially a supporting roller of the other plate and/or the auxiliary plate so that it will be safely guided. The said rail is preferably parallel to and flush with the table plate.

With an embodiment of the invention which is very simple to be assembled. the guiding rail is formed by one leg of the angle profile while its other leg serves as connecting leg. the lifting member preferably being connected to the bottom side of the guiding rail.

ln order to assure that both plates are well guided independently of each other. the guiding paths for the supporting member of the two plates as well as the supporting members when seen in pull-out direction are offset with regard to and adjacent to each other while preferably the supporting member of the auxiliary plate is closer to the longitudinal central plane of the table plate. In this way. the supporting members can also in pushed-in position be located nearly adjacent to each other. Furthermore, as a result of the just described arrangement. it can be assured that the supporting member of the auxiliary plate will also even with a great push-in depth not move onto the ramp.

In order to avoid an accidental taking along of the other plate at the start of the pull-out movement of the auxiliary plate. the other plate when occupying its pushed-in position is provided with an arresting means which preferably is formed by an arresting cam which is adjacent to the rear end of said ramp and is furthermore formed by a pertaining supporting member snapping behind said arresting cam. A safe arresting is obtained when the arresting cam is formed by the front confinement ofa recess for the engagement ofsaid supporting member which confinement is preferably located at the level of the rear end of the ramp. in this way an easy disengagement of the arresting means will be assured. The arresting recess may in conformity with the circumference of the supporting roller have the contour of the partial circle. preferably less than a semi-circle.

The ramp can in a simple manner be formed from a strip which is bent out of the guiding rail and that end of which preferably forms the said recesses merges with a further bent out supporting strip arranged adjacent thereto so that the end of the ramp is safely supported.

Additionally. or instead of the described guiding path. the guiding means for the auxiliary plate and/or the other plate may be at least one and at least a twopart telescopic guiding means or the like while in particular two telescopic guiding means are arranged on both sides of the table plate. The telescopic guiding means are preferably arranged at the front end of the auxiliary plate.

in order to assure an unimpeded displacement of the plates and a relatively short length of the telescopic guiding means when pushed together. the intermediate section of the at least three-part telescopic guiding means is displaceably arranged relative to the auxiliary plate.

The stationary part of the telescopic guiding means may in a simple manner be connected to the guiding rail. preferably at the upper side thereof adjacent to the connecting plane so that the telescopic guiding means does not have to be separately assembled to the furniture piece or the like.

A particularly safe support for the table plate will be assured if the rear end of the auxiliary plate is guided so that it engages or rests on that section of the telescopic guiding means which is connected to the support. or if the other plate is guided on said section.

Referring now to the drawings in detail. the furniture piece shown therein comprises a cupboard-like body l. which has at its top side a cover plate forming a work plate 2. Directly below the cover plate 2 in the front wall 3 of the body 1, there is provided a horizontal slot like opening 4 which extends over the entire width of the furniture piece or body 1.

On the inner side of each side wall 5 of the furniture piece 1 there is provided a part of the fitting or attachment 6 according to the invention for mounting two plates 7, 8 adapted to be pulled out from and pushed into the furniture piece 1. The two fitting or attachment parts 6 are arranged symmetrically and as an image with regard to each other. The plate 7 which in the pulled-out position of the attachment is the front plate will henceforth be designated as auxiliary plate and the other plate 8 will henceforth be termed the main plate. The main plate 8 could also be formed by a table plate or the like which in such an instance would not be extensible and below which the auxiliary plate 7 could be pushed in or pulled out.

Each fitting 6 has a telescopic guiding means 9 for instance formed by tubes with square cross section. The cross sectional largest pipe section 10 of the telescopic guiding means is connected to the inner side of the pertaining side wall 5. In that telescopic section 10 which is connected to the supporting means there is displaceably mounted telescopic section 11 in which an additional telescopic section 12 is displaceably arranged so that each telescopic guiding means comprises three parts. The front end of the innermost telescopic section 12 is connected at the front end of the auxiliary plate 7 to a strip [3 by means of which the opening 4 is closed when the table plate is in pushed-in position.

At the rear end of the auxiliary plate 12 at the bottom side thereof there are provided two intermediate members 18 which are arranged adjacent to each other and in spaced relationship to each other. These intermedi ate members 18 are adjacent to the inner side of the telescopic guiding means 9 and are pivotable about a common axis. The intermediate members 18 are in the manner of one-arm levers extending freely toward the rear and are pivotally mounted for pivoting about a horizontal shaft 19 which is perpendicular with regard to the pull-out direction indicated by the arrow l6. The intermediate members 18 are journaled on vertical legs of bearing angles l7. The members 18 are so arranged that their rear ends. when plate 8 is in its fully pushedin position, are located below the front end of plate 8. At the rear end of each lever arm 20 formed by a plate. a running member 21 is provided at the lateral surface of said lever arm 20 which lateral surface is located toward the longitudinal central plane of the table plate. The member 21 projects beyond that lateral surface and has an upper rounded running surface 22 for engagement with the bottom side of the main plate 8 and also has a lower rounded running surface 23 for en gagement with a lifting member 15. The surfaces 22 and 23 are curved about axes parallel to the pivot shaft 19, in such a way that the member 21 is flat-oval. The respective lifting member 15 is provided on a pertaining fitting part [4 in the form of an obtuse angle V- shaped bent wire piece. said fitting part l4 being connected to the inner side of the side wall 5 of the furniture piece. The V-shaped angle has its apex pointing upwardly and is adapted to be engaged by the running member 2l when the main plate 8 is fully pushed in. Each intermediate member 18 is spring urged to its lifting position by a leg spring 24 located in the pivot axis of said intermediate member 18.

When the plates 7, 8 are from their pulled-out position according to FIG. I pushed inwardly against the direction of the arrow [6, first the auxiliary plate 7 moves the main plate 8 in front thereofwhile the plates 7, 8 engage each other with those edges 25, 26 which face each other and are located at a right angle to the planes of the plates. Rotatably journaled on the rear ends of the plates 7, 8 respectively on both sides there are two supporting rollers 34. 35 which are rotatable about horizontal axes extending at a right angle to the pull-out direction indicated by the arrow 16. The supporting rollers 34 of the auxiliary plate 7 are journaled behind the rear end of said auxiliary plate at the same legs of the bearing angle 17 as the intermediate members 18 but on those sides of the legs which face away from each other. The supporting rollers 35 of the main plate 8 are at a slight distance located in front of the rear end of plate 8 and when viewed in pull-out direction indicated by arrow 16 are relative to the supporting rollers 34 offset toward the outside in such a way that they are located directly adjacent to those inner surfaces of the telescopic sections 10 which face each other. Associated to the supporting rollers 34, 35 is a common guiding rail 36 which is parallel to the table plane. This rail 36 is formed by an inwardly directed leg of the connecting part 14 of the pertaining fitting part 6. The other leg 37 of which serves for connecting the fitting part 6 and the telescopic section 10 to the inner surface of the side wall 5 of the furniture piece. The pertaining telescopic section 10 is connected to the top side of the rail leg 36 and extends only slightly over more than half of the length of leg 36. The guiding rail 36 forms two guiding paths located adjacent to each other for the supporting rollers 34, 35 which are offset with regard to each other.

At the rear end of the top side of each guiding rail 36 in the extension of the guiding path for the pertaining supporting roller 35 of the main plate 8 there is provided an inclined ascending ramp 27 which is formed by a strip bent out of the guiding rail 36 and onto which plate 8 moves with its roller 35 when plate 8 is pushed in so that its rear end will be lifted. Simultaneously with the movement of the main plate 8 onto the ramp 27 the running members 21 of the intermediate members 18 move onto the lifting members 15 so that the intermediate members are in conformity with FIG. 5 pivoted in clockwise direction and the plate 8 is also lifted at its front end to such an extent that the auxiliary plate 7 can be pushed below the plate 8 when it is pushed in further. The main plate 8 may have its lateral marginal zones resting on the top sides of the telescopic sections 10.

The main plate 8 may in conformity with FIG. 6 be pushed inwardly to such an extent that its supporting rollers 35 respecively snap behind a resting cam 38 located at the end of the pertaining ramp 27. Each resting cam 38 is formed by the front confinement of an arresting recess 39 which is open toward the top but over an area less than a semi-circle for receiving the pertaining supporting roller 35. The arresting recesses 39 are formed by the ends of the bent strips 27. These ends merge respectively with strip 40 bent out of a guiding rail 36. Strip 40 is relative to strip 27 offset toward the longitudinal plane of the table plate and is located approximately parallel to the ramp 27 so that on one hand satisfactory strength is assured while on the other hand a certain spring ofthe strip 27 will be possible when the supporting rollers 35 snap into the recess 39. The respective lifting member 15 is by means of transversely bent off leg ends connected to the bottom side of the pertaining guiding rail 36 preferably by welding.

When the plates 7 and 8 are in their pulled-out condition, the intermediate members 18 with their running members 21 likewise engage the bottom side of the main plate 8 in view of the thrust of springs 24. This thrust is, however, less than the force of weight of the main plate 8 acting thereagainst so that at any rate it will be assured that the main plate 8 will drop into the plane of the auxiliary plate 7. The intermediate members 18 thus do not have to be specifically limited in their movement by abutment means.

The upper plane connecting legs 29 of the bearing angles 17 which protrude rearwardly beyond the auxiliary plate 7 form in pulled-out condition of the plates :1 support for the front end of the auxiliary plate 8 so that the same are sufficiently supported. Connected to the bottom side of the rear end of the auxiliary plate 7 is a follower bearing 30 which is located in the longitudinal central plane of the table plate and projects beyond the rear end of the auxiliary plate 7 so that it likewise forms a support for the front end of the main plate 8. This support has an upwardly directed tapered mandrel 28 which in lowered position of the main plate 8 engages in a centering bore provided on plate 8 so that a very precise lateral alignment of the main plate 8 will be obtained. The follower bearing 30 has a recess which forms a passage for passing a pull rod 31 therethrough. The rear end of the pull rod 31 which pull rod extends to this rear end at an acute angle toward the main plate 8 downwardly at an incline merges through the intervention of an angled off portion 32 with a connecting section which is connected to the bottom side of the main plate 8. At the front end of the pull rod 31 there is provided an abutment 33 which is adjustable in the longitudinal direction of pull rod 3i. Then pulling out the plates 7. 8 from the completely pushed in position according to FIG. 6. the follower bearing 30 will at the instant of the lowering of the main plate 8 toward the follower bearing 30 move on the ramp so that a positive connection in the pulling out direction indicated by arrow 16 is established between the auxiliary plate 7 and the main plate 8 whereby the plate 8 in response to a further pull-out of the auxiliary plate 7 is taken along in the pull-out direction and jumps out of the recess 39.

it is. of course. to be understood that the present invention is, by no means. limited to the specific showing in the drawings but also comprises any modifications within the scope of the appended claims.

What is claimed is:

l. in a mechanism for supporting a main plate and an auxiliary plate in a cabinet or the like for parallel substantially linear movement of at least the auxiliary plate form retracted position inside the cabinet to extended position outside the cabinet with the main plate above the auxiliary plate in retracted position of the auxiliary plate and disposed at the cabinet end of the auxiliary plate when the latter is in extended position; said mechanism comprising; telescopic guide means having a first part for connection to the cabinet on the inside thereof and a second part for connection to the underneath side of said auxiliary plate. said guide means guiding said auxiliary plate in linear movement in parallelism with itself between retracted and extended positions. and lifting means operable when the auxiliary plate is moved in retracting direction from extended position for lifting said main plate to permit the auxiliary plate to move into the cabinet beneath the main plate, said lifting means comprising a lift cam stationary in the cabinet and a follower connected to the auxiliary plate and interposed between said lift cam and said main plate.

2. A mechanism according to claim 1 in which said main plate is also movable in parallelism with itself between a retracted position inside the cabinet and an extended position outside the cabinet. and actuating means is provided for moving said main plate between retracted and extended positions thereof by movement of said auxiliary plate between retracted and extended positions.

3. A mechanism according to claim l in which said follower is pivotally connected to said auxiliary plate for swinging movement about an axis perpendicular to the direction of movement of said auxiliary plate.

4. A mechanism according to claim I in which said lift cam and follower are disposed beneath said main plate.

5. A mechanism according to claim 4 in which said follower comprises an element engageable with said lift cam and a lever connected to said element and pivotally connected to said auxiliary plate.

6. A mechanism according to claim in which said lever is spring biased in lifting direction, said lever being laterally offset from said lift cam. said element being mounted on the side of said lever engaging said lift cam.

7. A mechanism according to claim 6 in which said element has the ends rounded with one end engageable with said lift cam and the other end engageable with said main plate.

8. A mechanism according to claim 1 in which said lift cam is a wire extending in the direction of movement of said auxiliary plate and convex upwardly when viewed from the side. said lift cam being stationarily mounted in said cabinet.

9. A mechanism according to claim I which includes a support plate connected to the bottom of said auxiliary plate and protruding from the end of said auxiliary plate which is nearest the cabinet in extended position of the auxiliary plate and adapted supportingly to engage the adjacent end of the main plate when the auxiliary plate is in extended position.

10. A mechanism according to claim 1 which includes a said lift cam and a said follower near each side edge of said plates.

ll. A mechanism according to claim I which includes a support plate connected to the bottom of said auxiliary plate and protruding from the end of said auxiliary plate which is nearest the cabinet in extended position of the auxiliary plate and adapted supportingly to engage the adjacent end of the main plate when the auxiliary plate is in extended position. a lever pivoted to said support plate and extending rearwardly. said follower being mounted on the rearward end of said lever.

[2. A mechanism according to claim 2 in which said actuating means comprises a pull rod connected at one end to the underside of the end of said main plate which is nearest the cabinet in extended position of the main plate and extending longitudinally beneath the main plate to near the opposite end thereof. and cooperating elements of abutment means on said auxiliary plate and said rod which interengage when the auxiliary plate is pulled out from beneath the main plate during movement from retracted position toward extended position to cause the main plate to follow the auxiliary plate during further movement toward extended position of the plates.

13. A mechanism according to claim 12 in which said pull rod is longitudinally resilient and at the said one end has an angled off portion extending to said main plate. said pull rod inclining toward the main plate from said angled off portion toward the other end of the pull rod.

14. A mechanism according to claim 2 which includes interengaging elements of a pin and socket on the ends of said plates which are adjacent in extended position of said plates and interengageable when the plates are in end to end relation.

15. A mechanism according to claim 14 in which said auxiliary plate comprises a support member protruding therefrom beneath the adjacent end of the main plate when the plates are in extended position. said pin upstanding from said support member.

16. A mechanism according to claim 2 in which the adjacent ends of said plates when in extended position are in substantially abutting relation.

17. A mechanism according to claim 2 which includes a longitudinal rail in said cabinet. a roller on the bottom of said main plate near the end which is adjacent the cabinet in extended position of the main plate. and an upwardly inclined ramp on said rail for lifting engagement with said roller as said main plate approaches retracted position.

18. A mechanism according to claim 17 in which said rail is one leg of an angle having the other leg connected to said cabinet, said lift cam being connected to said other leg of the rail.

19. A mechanism according to claim 17 in which said auxiliary plate also has a roller thereon engaging said rail, the roller on said main plate being laterally offset from the roller on said auxiliary plate when viewed in the longitudinal direction of said rail.

20. A mechanism according to claim 19 which includes a said rail at each side of the plates. a roller on each plate for each rail. the rollers on said auxiliary plate being offset toward each other from the rollers on the main plate 21. A mechanism according to claim 17 which includes an upwardly opening recess in said ramp to receive the roller on the main plate when the main plate is in retracted position.

22. A mechanism according to claim 21 in which said ramp is formed by a strip struck out from said rail 23. A mechanism according to claim 1 which includes a said telescopic guide means at each side of said auxiliary plate the said parts of each guide means being in the form of rectangular tubing.

24. A mechanism according to claim I in which said telescopic guiding means comprises three rectangular tubes in sliding telescopic engagement. the largest of said tubes forming said first part and being fixed in said cabinet and the smallest of said tubes forming said second part and being fixed to said auxiliary plates.

25. A mechanism according to claim 24in which said main plate rests on said first part in extended position of said auxiliary plate while said auxiliary plate rests on said first part when in retracted position.

26. A mechanism according to claim 1 which includes support rail means in said cabinet extending parallel to the direction of movement of said auxiliary plate said guiding means being shorter in the longitudinal direction than said rail means. 

1. In a mechanism for supporting a main plate and an auxiliary plate in a cabinet or the like for parallel substantially linear movement of at least the auxiliary plate form retracted position inside the cabinet to extended position outside the cabinet with the main plate above the auxiliary plate in retracted position of the auxiliary plate and disposed at the cabinet end of the auxiliary plate when the latter is in extended position; said mechanism comprising; telescopic guide means having a first part for connection to the cabinet on the inside thereof and a second part for connection to the underneath side of said auxiliary plate, said guide means guiding said auxiliary plate in linear movement in parallelism with itself between retracted and extended positions, and lifting means operable when the auxiliary plate is moved in retracting direction from extended position for lifting said main plate to permit the auxiliary plate to move into the cabinet beneatH the main plate, said lifting means comprising a lift cam stationary in the cabinet and a follower connected to the auxiliary plate and interposed between said lift cam and said main plate.
 2. A mechanism according to claim 1 in which said main plate is also movable in parallelism with itself between a retracted position inside the cabinet and an extended position outside the cabinet, and actuating means is provided for moving said main plate between retracted and extended positions thereof by movement of said auxiliary plate between retracted and extended positions.
 3. A mechanism according to claim 1 in which said follower is pivotally connected to said auxiliary plate for swinging movement about an axis perpendicular to the direction of movement of said auxiliary plate.
 4. A mechanism according to claim 1 in which said lift cam and follower are disposed beneath said main plate.
 5. A mechanism according to claim 4 in which said follower comprises an element engageable with said lift cam and a lever connected to said element and pivotally connected to said auxiliary plate.
 6. A mechanism according to claim 5 in which said lever is spring biased in lifting direction, said lever being laterally offset from said lift cam, said element being mounted on the side of said lever engaging said lift cam.
 7. A mechanism according to claim 6 in which said element has the ends rounded with one end engageable with said lift cam and the other end engageable with said main plate.
 8. A mechanism according to claim 1 in which said lift cam is a wire extending in the direction of movement of said auxiliary plate and convex upwardly when viewed from the side, said lift cam being stationarily mounted in said cabinet.
 9. A mechanism according to claim 1 which includes a support plate connected to the bottom of said auxiliary plate and protruding from the end of said auxiliary plate which is nearest the cabinet in extended position of the auxiliary plate and adapted supportingly to engage the adjacent end of the main plate when the auxiliary plate is in extended position.
 10. A mechanism according to claim 1 which includes a said lift cam and a said follower near each side edge of said plates.
 11. A mechanism according to claim 1 which includes a support plate connected to the bottom of said auxiliary plate and protruding from the end of said auxiliary plate which is nearest the cabinet in extended position of the auxiliary plate and adapted supportingly to engage the adjacent end of the main plate when the auxiliary plate is in extended position, a lever pivoted to said support plate and extending rearwardly, said follower being mounted on the rearward end of said lever.
 12. A mechanism according to claim 2 in which said actuating means comprises a pull rod connected at one end to the underside of the end of said main plate which is nearest the cabinet in extended position of the main plate and extending longitudinally beneath the main plate to near the opposite end thereof, and cooperating elements of abutment means on said auxiliary plate and said rod which interengage when the auxiliary plate is pulled out from beneath the main plate during movement from retracted position toward extended position to cause the main plate to follow the auxiliary plate during further movement toward extended position of the plates.
 13. A mechanism according to claim 12 in which said pull rod is longitudinally resilient and at the said one end has an angled off portion extending to said main plate, said pull rod inclining toward the main plate from said angled off portion toward the other end of the pull rod.
 14. A mechanism according to claim 2 which includes interengaging elements of a pin and socket on the ends of said plates which are adjacent in extended position of said plates and interengageable when the plates are in end to end relation.
 15. A mechanism according to claim 14 in which said auxiliary plate comprises a support member protruding therefrom benEath the adjacent end of the main plate when the plates are in extended position, said pin upstanding from said support member.
 16. A mechanism according to claim 2 in which the adjacent ends of said plates when in extended position are in substantially abutting relation.
 17. A mechanism according to claim 2 which includes a longitudinal rail in said cabinet, a roller on the bottom of said main plate near the end which is adjacent the cabinet in extended position of the main plate, and an upwardly inclined ramp on said rail for lifting engagement with said roller as said main plate approaches retracted position.
 18. A mechanism according to claim 17 in which said rail is one leg of an angle having the other leg connected to said cabinet, said lift cam being connected to said other leg of the rail.
 19. A mechanism according to claim 17 in which said auxiliary plate also has a roller thereon engaging said rail, the roller on said main plate being laterally offset from the roller on said auxiliary plate when viewed in the longitudinal direction of said rail.
 20. A mechanism according to claim 19 which includes a said rail at each side of the plates, a roller on each plate for each rail, the rollers on said auxiliary plate being offset toward each other from the rollers on the main plate.
 21. A mechanism according to claim 17 which includes an upwardly opening recess in said ramp to receive the roller on the main plate when the main plate is in retracted position.
 22. A mechanism according to claim 21 in which said ramp is formed by a strip struck out from said rail.
 23. A mechanism according to claim 1 which includes a said telescopic guide means at each side of said auxiliary plate, the said parts of each guide means being in the form of rectangular tubing.
 24. A mechanism according to claim 1 in which said telescopic guiding means comprises three rectangular tubes in sliding telescopic engagement, the largest of said tubes forming said first part and being fixed in said cabinet and the smallest of said tubes forming said second part and being fixed to said auxiliary plates.
 25. A mechanism according to claim 24 in which said main plate rests on said first part in extended position of said auxiliary plate while said auxiliary plate rests on said first part when in retracted position.
 26. A mechanism according to claim 1 which includes support rail means in said cabinet extending parallel to the direction of movement of said auxiliary plate, said guiding means being shorter in the longitudinal direction than said rail means. 